1. Field of the Invention
One or more embodiments of the present invention relate to secondary batteries.
2. Description of the Related Art
Due to reaction with an active material and an electrolyte, gases, such as CO2 or H2, are generated in a secondary battery. When these gases are formed in a space inside the secondary battery, the active material in certain portions of the secondary battery may undesirably lose its function or movement of lithium ions in an electrolyte may be hindered, resulting in reduction of the lifespan of the secondary battery. Moreover, if the generated gas accumulates, an internal pressure of the secondary battery may increase, which may lead to an explosion of the secondary battery.
Thus, to improve the lifespan and stability of the secondary battery, the generated gas needs to be discharged to the outside of the secondary battery to prevent loss of the function of the active material and to remove bubbles formed in the electrolyte.